Body composition analysis by bioelectrical impedance in chronic maintenance dialysis patients: Comparisons to the nutrition national health and examination survey III

Objective: To compare bioelectrical impedance analysis derived parameters in chronic maintenance dialysis patients to those obtained in National Health and Nutrition Examination Survey (NHANES) III. Design: Cross-sectional nutritional surveillance study. Setting: Hospital-based, not-for-profit chronic maintenance dialysis center. Patients: A total of 913 chronic maintenance dialysis patients and a subset of 10,263 subjects from NHANES III who underwent bioelectrical impedance analysis. Independent (Predictor) Variables: Bioelectrical impedance parameters including resistance, reactance, phase angle, and total body capacitance. Main Outcome Measures: Total body water, intracellular and extracellular water, body cell mass, fat free mass, fat mass. Results: Relative to NHANES III, end-stage renal disease patients have lower resistance (3%), reactance (26%), phase angle (28%); and intracellular water (9%) values, whereas extracellular water content is 17% higher (P < .001). In addition, body cell mass, fat free mass, and fat mass were lower in end-stage renal disease patients when compared with NHANES III subjects (9%, 3%, and 12%, respectively; P < .001). Conclusions: End-stage renal disease patients have a lower tissue mass than the general population and remain in a state of overhydration while on chronic maintenance dialysis therapy. (C) 2003 by the National Kidney Foundation, Inc.